Surface modified kaolin pigment and method thereof

Abstract

Provided herein are surface treated pigments and methods of making and using the surface treated pigments. The surface treated pigments can comprise a mineral pigment surface treated with a hydrophilic latex composition and a hydrophobic material, which produce a film on an outer surface of the pigment. The hydrophobic material can be selected from a silane, a siloxane, or a siloxane/silicone resin blend, wax, fatty acid, styrene-butadiene latex, or a mixture thereof. The hydrophilic latex composition can be selected from a straight (meth)acrylic latex emulsion, a styrene-(meth)acrylic latex emulsion, or a blend thereof. The surface treated pigment has a surface energy that is less than a surface energy of the mineral pigment alone, a water contact angle of at least 90° and a dodecane contact angle of less than 150°.

1 . A surface treated pigment comprising:
 a mineral pigment surface treated with a hydrophilic latex composition selected from a straight (meth)acrylic latex emulsion, a styrene-(meth)acrylic latex emulsion, or a blend thereof, and a hydrophobic material selected from a silane, a siloxane, or a siloxane/silicone resin blend, wax, fatty acid, styrene-butadiene latex, or a mixture thereof;   wherein at least one of the hydrophilic latex composition and the hydrophobic material produces a film on an outer surface of the mineral pigment, and   
       wherein the surface treated pigment has a surface energy that is less than a surface energy of the mineral pigment alone. 
     
     
         2 . The surface treated pigment of  claim 1 , wherein the difference between the surface energy of the surface treated pigment and the surface energy of the mineral pigment is 1 mN/m or greater, or from 1 mN/m to 5 mN/m. 
     
     
         3 . The surface treated pigment of  claim 1 , wherein the surface energy of the surface treated pigment is less than a surface energy of a mineral pigment treated with the hydrophilic latex composition alone. 
     
     
         4 . The surface treated pigment of  claim 3 , wherein the difference between the surface energy of the surface treated pigment and the surface energy of the mineral pigment treated with the hydrophilic latex composition alone is 0.2 mN/m or greater, or from 0.2 mN/m to 2 mN/m. 
     
     
         5 . The surface treated pigment of  claim 1 , wherein the surface energy of the surface treated pigment is less than a surface energy of a mineral pigment treated with the hydrophobic material alone. 
     
     
         6 . The surface treated pigment of  claim 5 , wherein the difference between the surface energy of the surface treated pigment and the surface energy of the mineral pigment treated with the hydrophobic material alone is 0.2 mN/m or greater, or from 0.2 mN/m to 2 mN/m. 
     
     
         7 . The surface treated pigment of  claim 1 , wherein the surface treated pigment has a surface energy of less than 20 mN/m, or from 10 to 18 mN/m. 
     
     
         8 . The surface treated pigment of  claim 1 , wherein a surface of the surface treated pigment exhibits a water contact angle of at least 90° and a dodecane contact angle of less than 150° or less than 90°. 
     
     
         9 . The surface treated pigment of  claim 8 , wherein both the water contact angle and the dodecane contact angle of the surface treated pigment are higher than a water contact angle and a dodecane contact angle of the mineral pigment. 
     
     
         10 . The surface treated pigment of  claim 8 , wherein both the water contact angle and the dodecane contact angle of the surface treated pigment are higher than a water contact angle and a dodecane contact angle of a mineral pigment treated with the hydrophobic material alone. 
     
     
         11 . The surface treated pigment of  claim 8 , wherein the water contact angle of the surface treated pigment is less than a water contact angle of a mineral pigment treated with the hydrophilic latex composition alone and the dodecane contact angle of the surface treated pigment is greater than a dodecane contact angle of a mineral pigment treated with the hydrophilic latex composition alone. 
     
     
         12 . The surface treated pigment of  claim 1 , wherein the surface treated pigment is less wettable by water, compared to the mineral pigment or a mineral pigment treated with the hydrophilic latex composition alone, as determined by ASTM 7315-17. 
     
     
         13 . The surface treated pigment of  claim 12 , wherein a mixture comprising the surface treated pigment in contact with water for a period of at least 120 minutes, has a turbidity of 1.5 NTU or less, or 1.0 NTU or less. 
     
     
         14 . The surface treated pigment of  claim 1 , wherein the mineral pigment is calcined prior to surface treatment. 
     
     
         15 . The surface treated pigment of  claim 1 , wherein the mineral pigment is selected from the group consisting of kaolin, bentonite, mica, talc, attapulgite, silica, calcium carbonate, halloysite, wollastonite, nepheline syenite, feldspar, diatomaceous earth, and zeolite. 
     
     
         16 . The surface treated pigment of  claim 15 , wherein the mineral pigment includes kaolin, preferably calcined kaolin. 
     
     
         17 . The surface treated pigment of  claim 1 , wherein the mineral pigment has an average particle size of less than 10 microns, preferably an average particle size ranging from 0.1 to 10 microns, more preferably an average particle size ranging from 0.1 to 2 microns. 
     
     
         18 . The surface treated pigment of  claim 1 , wherein the hydrophobic material includes an organosilane monomer having a structure defined by the general Formula I below:
   (R 1 )—(Si)—(R 2 ) 3    (I)
   
       wherein R 1  is a C 1 -C 8  substituted or unsubstituted alkyl or a C 2 -C 8  substituted or unsubstituted alkene and each of R 2  is independently a C 1 -C 8  substituted or unsubstituted alkyl group, a C 1 -C 8  substituted or unsubstituted alkoxy group, or a combination thereof. 
     
     
         19 . The surface treated pigment of  claim 1 , wherein the hydrophobic material includes an oligomeric or polymeric siloxane. 
     
     
         20 . The surface treated pigment of  claim 1 , wherein the hydrophobic material includes vinyltrimethoxysilane, vinyltriethoxysilane, vinyl tris(2-methoxyethoxy silane), vinyl triisopropoxysilane, gamma-methacryloxypropyl trimethoxysilane, (3-methacryloxypropyl)-trimethoxysilane, (3-methacryloxypropyl)-triethoxysilane, (3-methacryloxypropyl)-triisopropoxysilane, 2-methyl-2-propenoic acid 3-[tris-(1-methylethoxy)-silyl]-propyl ester, (3-methacryloxypropyl)-methyldiethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, oligomers thereof, polymers thereof, or combinations thereof. 
     
     
         21 . The surface treated pigment of  claim 1 , wherein the hydrophilic latex composition comprises a straight (meth)acrylic latex emulsion. 
     
     
         22 . The surface treated pigment of  claim 21 , wherein the straight (meth)acrylic latex emulsion comprises a copolymer derived from monomers comprising 80% or greater, preferably from 80% to less than 100% by weight of a (meth)acrylate monomer. 
     
     
         23 . The surface treated pigment of  claim 1 , wherein the hydrophilic latex composition comprises a styrene-(meth)acrylic latex emulsion. 
     
     
         24 . The surface treated pigment of  claim 23 , wherein the styrene-(meth)acrylic latex emulsion comprises a copolymer derived from monomers comprising 20% to 80% by weight of styrene and 20% to 80% by weight of a (meth)acrylate monomer. 
     
     
         25 . The surface treated pigment of  claim 21 , wherein the copolymer present in the straight (meth)acrylic latex emulsion or the styrene-(meth)acrylic latex emulsion is further derived from one or more additional monomers that include carboxylic acid monomers, crosslinkable functional monomers, (meth)acrylamide, or mixtures thereof. 
     
     
         26 . The surface treated pigment of  claim 21 , wherein the copolymer present in the straight (meth)acrylic latex emulsion or the styrene-(meth)acrylic latex emulsion has a glass transition temperature of 30° C. or less, preferably from −60° C. to 30° C., more preferably from −40° C. to less than 0° C. 
     
     
         27 . The surface treated pigment of  claim 1 , wherein the mineral pigment is surface treated with a straight (meth)acrylic latex emulsion as the hydrophilic latex composition and a silane as the hydrophobic material. 
     
     
         28 . The surface treated pigment of  claim 1 , wherein the hydrophilic latex composition and the hydrophobic material are in a weight ratio of from 1:4 to 4:1, from 1:3 to 3:1, preferably from 1:2 to 2:1. 
     
     
         29 . The surface treated pigment of  claim 1 , wherein the surface treated pigment comprises 0.2% by weight or greater, preferably from 0.2% to 5% by weight, more preferably from 0.5% to 2% by weight of the hydrophilic latex composition and the hydrophobic material, based on the weight of the surface treated pigment. 
     
     
         30 . An aqueous coating system comprising a surface treated pigment according to  claim 1 . 
     
     
         31 . The aqueous coating system of  claim 30 , comprising at least 0.2% by weight, preferably from 0.2% to 30% by weight, more preferably from 0.5% to 10% by weight of the surface treated pigment. 
     
     
         32 . The aqueous coating system of  claim 30 , further comprising a polymer binder system. 
     
     
         33 . The aqueous coating system of  claim 32 , comprising at least 10% by weight, preferably from 10% to 99% by weight, more preferably from 10% to 95% by weight of the polymer binder system. 
     
     
         34 . The aqueous coating system of  claim 32 , wherein the polymer binder system comprises a latex polymer binder. 
     
     
         35 . The aqueous coating system of  claim 34 , wherein the latex polymer binder comprises a polymer or copolymer derived from synthetic resins, natural resins, (meth)acrylics, polyurethanes, polyesters including unsaturated and saturated polyesters, melamine polymers, epoxy polymers, alkyds, phenolic polymers, ureaformaldehyde polymers, polyalkylenes including polyethylenes and polypropylenes, polystyrenes, polyamides, polyvinyl compounds, polyisoprenes, polybutadienes, polystyrene butadienes, or a combination thereof. 
     
     
         36 . The aqueous coating system of  claim 30 , further comprising an untreated mineral pigment. 
     
     
         37 . The aqueous coating system of  claim 36 , wherein the untreated mineral pigment is selected from titanium dioxide, clay, kaolin, mica, talc, natural silica, synthetic silica, natural silicates, synthetic silicates, feldspars, nepheline syenite, wollastonite, diatomite, barite, glass, calcium carbonate, or combinations thereof. 
     
     
         38 . The aqueous coating system of  claim 30 , wherein the aqueous coating system is a paint or and ink. 
     
     
         39 . The aqueous coating system of  claim 30 , wherein the aqueous coating system is an adhesive. 
     
     
         40 . The aqueous coating system of  claim 30 , wherein the substrate is a fabric, a fiber, a carpet, a concrete, a wood, a vinyl, a leather, a metal, a plastic, a ceramic, or a paper. 
     
     
         41 . A treated film derived from an aqueous coating system of  claim 30 , wherein the treated film exhibits stain and/or dirt resistance properties, wherein the stain and/or dirt produce a color change on a film, and wherein the color change of the treated film is reduced by a ΔE value of 0.1 or greater, greater than 0.1, or greater than 0.2 compared to the identical film formed from the untreated pigment, as determined by ASTM D2244-16. 
     
     
         42 . The treated film of  claim 41 , wherein the treated film exhibits a total color change value, ΔE, of from 0 to less than 10, or from 0 to less than 5, after 1 hour of contact with the stain and/or dirt, as determined by ASTM D2244-16. 
     
     
         43 . The treated film of  claim 41 , wherein the treated film exhibits stain resistance properties to both hydrophobic and hydrophilic stains. 
     
     
         44 . The treated film of  claim 41 , wherein the treated film further exhibits oil barrier properties, water barrier properties, oil and water barrier properties, and/or solvent barrier properties, as determined by ASTM D 4828-94. 
     
     
         45 . The treated film of  claim 41 , wherein the treated film exhibits resistance to coffee, mustard, ketchup, lipstick, ink, juice, wine, or combinations thereof. 
     
     
         46 . The treated film of  claim 41 , having a thickness of at least 0.5 microns, preferably a thickness of from 0.5-150 microns. 
     
     
         47 . A method of producing a surface treated pigment according to  claim 1 , comprising:
 mixing a mineral pigment with a hydrophilic latex composition selected from a straight (meth)acrylic latex emulsion, a styrene-(meth)acrylic latex emulsion, or a blend thereof, and a hydrophobic material selected from a silane, a siloxane, or a siloxane/silicone resin blend, wax, fatty acid, styrene-butadiene latex, or a mixture thereof, under conditions to surface treat the mineral pigment with the composition,   wherein at least one of the hydrophilic latex composition and the hydrophobic material produces a film on an outer surface of the pigment, and   
       wherein the surface treated pigment has a surface energy that is less than a surface energy of the mineral pigment alone. 
     
     
         48 . The method of  claim 47 , wherein the hydrophilic latex composition and the hydrophobic material are blended prior to mixing with the mineral pigment. 
     
     
         49 . The method of  claim 47 , wherein the hydrophilic latex composition and the hydrophobic material are mixed with the mineral pigment sequentially. 
     
     
         50 . The method of  claim 47 , wherein the mineral pigment is a calcined mineral pigment. 
     
     
         51 . The method of  claim 47 , wherein the mineral pigment is provided as a powder. 
     
     
         52 . The method of  claim 47 , wherein the mineral pigment provided as a slurry. 
     
     
         53 . The method of  claim 52 , wherein the slurry is dried by heating after mixing with the hydrophilic latex composition and/or the hydrophobic material. 
     
     
         54 . The method of  claim 47 , wherein the hydrophobic material comprises neat silane, neat siloxane, or mixtures thereof. 
     
     
         55 . The method of  claim 47 , wherein the hydrophobic material comprises a silane emulsion, a siloxane emulsion, or a mixture thereof. 
     
     
         56 . The method of  claim 46 , wherein mixing is carried out with a blender or a centrifuge for at least 30 minutes. 
     
     
         57 . The method of  claim 47 , wherein the hydrophilic latex composition and the hydrophobic material are in a weight ratio of from 1:4 to 4:1, from 1:3 to 3:1, preferably from 1:2 to 2:1. 
     
     
         58 . A method of producing an aqueous coating system comprising:
 mixing a surface treated pigment according to  claim 1  and a polymer binder system to form the aqueous coating system.   
     
     
         59 . The method of  claim 58 , further comprising an untreated mineral pigment. 
     
     
         60 . The method of  claim 58 , wherein the aqueous coating system is a paint or an ink. 
     
     
         61 . A method for improving the stain and/or dirt resistance properties of a surface, the method comprising applying an aqueous coating system of  claim 1  to the surface, wherein the aqueous coating system is a paint or ink. 
     
     
         62 . The method of  claim 61 , wherein the surface is a fabric, a fiber, a carpet, a concrete, a wood, a vinyl, a leather, a metal, a plastic, a ceramic, or a paper. 
     
     
         63 . The method of  claim 61 , wherein the aqueous coating system forms a treated film after drying, and wherein the treated film exhibits stain and/or dirt resistance properties, wherein the stain and/or dirt produce a color change on a film, and wherein the color change of the treated film is reduced by a ΔE value of 0.1 or greater, greater than 0.1, or greater than 0.2 compared to the identical film formed from the untreated pigment, as determined by ASTM D2244-16. 
     
     
         64 . The method of  claim 63 , wherein the treated film exhibits a total color change value, ΔE, from 0 to less than 10, or from 0 to less than 5, after 1 hour of contact with the stain and/or dirt, as determined by ASTM D2244-16. 
     
     
         65 . The method of  claim 63 , wherein the treated film exhibits stain resistance properties to both hydrophobic and hydrophilic stains. 
     
     
         66 . The method of  claim 63 , wherein the treated film further exhibits oil barrier properties, water barrier properties, oil and water barrier properties, and/or solvent barrier properties, as determined by ASTM D 4828-94. 
     
     
         67 . The method of  claim 63 , wherein the treated film exhibits resistance to coffee, mustard, ketchup, lipstick, ink, juice, wine, or combinations thereof.